Vacuum fueir-feed device



F.*G. WHITTINGTON.

VACUUM FUEL FEED DEVICE.

APPLICATION FILED IAN. 1o, 1921.

ptlltedsept. 20, 1921.

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FREDERIK G. WHITTINGTON, 0F CHICAGO, ILLINOIS, ASSIGNOR TO STEWART-WARNER SPEEDOMETER CORPORATION, OF CHICAGO, ILLINOIS, A. CORPORATION orVIRGINIA..

Application filed January 10, 1921.

To all whom t may concern.'

Be it known that LIFREDERTK G. WHIT- TINGTON, a citizen of the UnitedStates, residing at the city of Chicago, in the county of Cook and theState of Illinois, have invented certain new and useful Improvements inVacuum Fuel-fl? eed Devices, of which the following is a specication,reference being had to the accompanying drawings, forming a partthereof.

The purpose of this invention is to provide an improved construction ofvacuum fuel feed device for internal combustion engines for lifting thefuel from a tank lower than the engine carbureter to a source of supplywhich is positioned so as to supply the carbureter by gravity. Itconsists in the elements and features of construction shown anddescribed as indicated in the claims.

In the drawings Figure 1 is a vertical axial section of a deviceembodying this invention, the position of the moving parts being thatoccupied when the vacuum chamber is being supplied with the liquid drawnfrom the low tank, not shown.

Fig. 2 is a section similar to Fig. l, showing the position of themoving parts outside when the vacuum chamber is emptied by gravity tothe reserve chamber.

The drawings show only what is commonly known as the vacuum tank of thefuel feed device, with indications as to its connections with the mainlow tank, which is not shown, and with the engine intake manifold, whichis not shownq and with the carbureter, which is not shown; theseconnections being familiar and their relation to the operatingv devicelbeing well understood.

The device shown comprises a reserve or immediate supply chamber for thecarbureter, indicated at 2; the vacuum chamber, 3, suspended within thechamber, 2, the top plate, 4, to which the chamber, 2, and the chamber,3, are bothattached and by which they are rigidly united, and by whichthe vacuum chamber is closed at the top, the annular space, 5, betweenthe two chambers being closed at the top by the overlapping flanges, 2aand 3a, of the chambers, 2 and 3, respectively, which flanges serve asmeans of securing the two chambers to the top plate, et, by bolts, 6. 7is a liquid supply pipe Specification of Letters Patent.

Patented Sept. 20, 1921.

Serial 110.436,062.

vacuum chamber, so as to preventY delivering it on top of the fioathereinafter mentioned. Connection for suction is made by means of afitting, 12, screwed into the center of the top plate, 4;, connected bymeans of a pipe, 13, with the engine intake manifold, (not shown).Airinlet to the vacuum chamber is provided through a bushing or plug,16, screwed into the top plate, 4, having a relatively large verticalaperture la, extending through it,v and a relatively small rightangleshaped air inlet duct, 16", extending in from the side and terminatingat the upper end of the said bushingvor plug, whose said upper end isflat and constitutes a seat for a disk valve, 418, for which a chamber,2l, is formed by means of a coupling, 19, flanged at its upper end forengaging the projecting flange, 20a, of a fitting, 20, which is screwedonto the lower downwardly projecting end of a'lateral and down-turnedbranch, 12, of the suction connection fitting, 12. Said branch has aduct, 12b, leading from the main suction duct of the'fltting as a branchor by-pass'andextending through and opening at the said down-turned endof said lateral branch, 123, and there communicating through the centralduct, 20a, of the fitting, 2O` with the chamber 2l. F or a purposehereinafter explained there is formed in the fitting, 20, a relativelysmall air vent passage, 20", terminating at one end at the Y outersurface of said fitting, and at the other end openingrthrough the Hatseat at the lower end of said fitting through which also the centralaperture, 20, opens, so that both said central opening and said lateralvent passage are adapted to be closed by the disk valve, 1S, when saidvalve seats upwardly against the lower end of saidtting, 20, ashereinafter explained. The suction inlet at Vthe center of the vacuumchamber is controlled by the suction valve, 24, carried 0n the stem, 26,which carries a float, 25, operating upon rise of the liquid in thechamber to seat the suction valve, and upon fall of the liquid below apredetermined point to withdraw the suction valve from its seat againstthe suction tending to hold it thereon. Preferably the ioat has a rangeof movement along the stem, 26, between a lower stop, 26a, on which thefloat lodges at a predetermined low level of the liquid for adding itsunbuoyed weight to that of the stem and valve, 24, for pulling saidvalve from its seat against the suction tending to holdV it seated, andan upper stop, 26h,4

against which the float is buoyed up at a predetermined high level forseating the valve, 211; and, also preferably, the weight of the valveand stem, 26, is Venough to pull said valve from its seat againstsuction somewhat greater than the lowest which is adequate to lift theliquid from the main tank; and there isV interposed between the iioatand said upper stop, 26h, a light compression spring, 29, whoseresistance to compression is such that it is compressed enough foropening of the valve, 24, by something less than the full weight of saidvalve and stem,

so that as the float recedes under Vit yupon fall of the liquid levelfrom the high point at which the ioat causes the seating of the valve,the spring expanding and reducing its upward reaction against the valve,the latter will be opened by the weight of the valve and stem, suchopening occurring soonest when the suction is lightest and being delayedmore as the suction is higher. This spring, 29, will be desirably sorelated to the weight of the valve and stem and to the suction withrespect to stiffness and extent of expansion that when its resilientsupport of the valve is entirely withdrawn, 'leaving the full weight ofthe valve and stem available for opening the valve, such opening willoccur against suction predetermined as high enough to cause reasonablyprompt iilllng of the vacuum chamber. And when the suction is higherthan a predetermined degree, the valve will not be 'opened Vuntil thefloat has fallen so far as to lodge on the lower stop, 26D, and thelevel of liquid has further fallen so that the unsupported weight of thefloat added to the weight of thel valve and stem will be adequate toopen the valve against the high suction. The vacuum chamber, 3,discharges into the chamber, 2, through a fitting, 27, which at itsupper end is provided with a guide, 27, for the lower end of the stem,25, and an angle fitting, 28, screwed onto the lower end of saidfitting, 27, the end of whose horizontal limb is preferably oblique,facing obliquely upward, and carries a check valve` 30. which isnormally seated by gravity over the discharge end of the liquid passage,so as to be opened by the gravity flow of the liquid from the vacuumchamber into the chamber, 2. This construction is familiar in this artand is not upon starting the engine, suction through l the suctionconnection, 10, produces a partialV vacuum in the vacuum chamber, 3,

causing the liquid to be lifted through the pipe, 8, from the low levelsupply tank and discharged into the saidL vacuum chamber, graduallylifting the float, 25, and eventually at a predetermined high level,carry` ing the valve, 24, so'near to its seat at theY port of thesuction connection, 10, that the suction operating therethrough `willApull it to its seat, which will occur varyingly ac Y cording to thesuction, occurring sooner,-' that is, at lower level of the l1qu1d,-whenthe suction 1s high, and a little later when the suction is low. Duringthe process thus far described, the disk valve, 18, being initiallylodged by gravity upon the seat at the upper end of the bushing or plug,16, is held firmly to its seat by the suction resulting from the partialvacuum created in the vacuum chamber, 3, excluding air or atmosphericpressure form the vacuum chamber, 8, while said chamber is filling withliquid for lifting the float. Upon the closing ofv the suction valve bythe rise of the float as above mentioned, the liquid will continue toiow in through the pipe, 8, until the vacuum in the vacuum chamber isreduced ta the'minimum which will balance the liquid column extendingback to the low main sup ply tank. Meanwhile thesuction operatingthrough the duct, 12b, in the lateral branch, 12a, of the suctionconnection, continuing unchanged during the reduction of vacuum in thevacuum chamberV operating through the duct, 16at0 hold the valve, 18,upon its seat, it results that at some point in the process of reductionofv vacuum in the chamber, 3, lthe suction operating through the by-passduct, 12b, while atmospheric pressure through the air inlet, 165,continues, lifts this valve 18, from its seat on the upper flat end ofthe bushing or plug, 16, admitting atmospheric pressure" will continueuntil the float, 25, withdrawl ing from the upper stop, 26a, permits thespring, 29, t0 expand and diminish its upholding action on the valve tosuch extent that the unsupported weight of the valve and stem exceedsthe suction holding it on its seat, or in case the suction is inadequateto sustain the entire weight of the valve and stem, then until the floathas so far fallen as to lodge upon the lower stop, 26h, and becomeunsubmerged s0 as to add enough of its weight to the weight of the valveand stem to pull the valve olf its seat against the high suction. Theopening of the valve admits full suction to the vacuum chamber, 5, whichwill operate immediately to seat the valve, 18, cutting off exterior airpressure; and thereupon the vacuum chamber will be re-lled by the liquidlifted by suc'- tion from the low tank, and the previously describedoperation will be repeated until the liquid rises in the chamber, 2,-andis thereby upheld in the chamber, 3,-to the high level at which thefloat holds the suction valve closed. And at that condition, the devicewill cease to operate until the withdrawal of liquid from the chamber,2, to supply the carbureter, lowers the level in the chamber, 2, andalso in the vacuum chamber, 3, to a point at which the suction valve isopen as above described.

It will be observed that the vent or relief duct, 20D, must be smallerthan the duct, 20a, through which the suction operates for producingpartial vacuum in the valve chamber, 21, above the valve, 18, and thatthe said last mentioned duct is smaller than the duct, 16, through whichsuction from the vacuum chamber reaches the lower side of said valve,18, and that the duct, 16a, is necessarily larger than the atmosphereinlet angle-shaped duct, 16". These dimensional relations result firstin the production of a limited partial vacuum above the valve, 18,

less than that produced in the vacuum chamber, 5, because of the vent orrelief duct, 20h; that when said valve is seated against its upper seatand off' from its lower seat while the suction valve, 24, is open, alimited partial vacuum is produced in the valve chamber, 21, below saidvalve, 18, less than the partial vacuum produced in the chamber, 3, tothe extent that the atmosphere entering through the angle duct, 1Gb,relieves the suction operating through the duct, 16": The result is thatthe suction operating through the duct, 12a, when the valve, 18, isseated upwardly, closing the vent or relief duct, 20h, is adequate tohold this disk, valve, 18, upon its upper seat against the diminishedpartial vacuum due to the differences between the two ducts, 16a and16h, operating at the lower side of said disk valve.

The result of the above described construction, it will be seen is thatthe atmosphere inlet controlling valve, 18, first seated by gravity onits lower seat, and then held to that seat by the suction from thepartial vacuum in the vacuum chamber, 3, while that chamber is iillingwith liquid, will not be opened nor make any movement to leave its saidlower seat, until the suction valve, 25, becomes seated, cutting off thesuction from the chamber, 3, while said suction continues to operatethroughthe by-pass duct, 12b, for producing partial vacuum in the valvechamber, 21, above the atmospherecontrolling valve, 18; and that whenthe suction valve, 25, is thus seated, the atmosphere controlling valvebeing thus opened by the suction, will be held open, admittingatmosplieric pressure to the vacuum chamber, 3, until the suction valve,25, is again opened, admitting suction to said chamber, and producing apartial vacuum on the lower side of the atmosphere valve; whereuponimmediately said valve will be closed by the superior suction at thelower side added to gravity,-the weight of the valve. Third, that whenthe engine stops, terminating suction act-ionMthrough both the main andbypass passages-on both valves, the suction valve will drop from itsseat and the atmosphere valve will fall to its seat, but will be free tooperate as a check valve for admitting atmospheric pressure so that anyliquid contained in the vacuum chamber, 3, when the engine stops, willfall at once into the chamber, 2, unless said chamber is already full tothe height of the liquid in the vacuum chamber. This last result, whilenot novel in vacuum fuel feed devices, is of considerable importance forreasons well understood, and it is considered important to point outthat the result is not prevented or defeated by the nove-l constructionand operation of the valves as above described.

I claim 1. ln a vacuum fuel feed device having a vacuum chamber providedwith liquid inlet and outlet; suction connections, and an air inlet, theair inlet comprising a valve chamber having an air inlet port and a portleading to the vacuum chamber; a valve in said valve chamber which seatsat both said ports, whereby it cuts ofl' communication between them; asuction duct leading from said valve chamber at the opposite side ofsaid valve from said first mentioned ports, and means for partiallyoffsetting the suction operative through said duct to reduce the partialvacuum in said valve chamber at said opposite side of the valve therein.

2. In the construction defined in claim 1, foregoing, the means foroffsetting the suction in said valve chamber being in air inlet portadmitting air to said valve chamber at said opposite side of the valvefrom the two first mentioned ports.

3. In the construction defined in claim 1 foregoing, the means foroffsetting the suction in said valve chamber being an air leal; portadmitting air to said valve chamber at said opposite side of the valvefrom the two ports first mentioned, said leali port opening through thevalve seat at said opposite side for facilitating the release of thevalve from said seat.

t. In a vacuum fuel feed device having a vacuum chamber with a liquidinlet and outlet, a suction connection and an air inlet; a'valve whichcontrols the suction inlet, a float for operating said valve to close itby rise of the liquid level and open it upon the fall of said level inthe vacuum chamber; a valve which controls the air inlet positioned forbeing seated by the suction and also for being opened by the incomingair, and a connection for suction to operate on said valve in theopposite direction from and in less degree than the suction de 1ivedfrom the vacuum chamber.

5. In the construction defined in claimV 4., foregoing, the air inletcomprising two ports opening through the same seat, one leading to theair source and the other-to the vacuum chamber, and a valve whichcontrols the air inlet seating upon said seat to close both said portsat the same time.

6. In the construction defined in claim l, foregoing, the secondmentioned suction con* nection being a branch of the first.

7. In a vacuum fuel feeding device having a vacuum chamber provided Withliquid inlets and outlets, suction connection and air inlet, a valve forcontrolling the suction connection positioned for being seated by thesuction and opened by gravity; a iioat in the chamber operativelyconnected with said valve for lifting it to closed position when thefloat rises; said connection comprising a spring which reacts betweenthe float and the valve for yieldingly transmitting the lifting movementof the fioat to the valve in opposition to the gravity opening action infavor of the suction seating thereof.V

8. In the construction described in claim 4t, foregoing, an air leak atthe side of the air inlet valve and which the suction in opposition tothat of the vacuum chamber is admitted, the suction controlling valve inthe vacuum chamber being positioned for FREDERIK G. WHITTINGTON.

